U.S. patent application number 13/083165 was filed with the patent office on 2011-10-06 for magnetic screen clamping.
This patent application is currently assigned to M-I L.L.C.. Invention is credited to Brian S. Carr, Benjamin L. Holton, James A. Marshall, JR., Michael A. Timmerman.
Application Number | 20110240531 13/083165 |
Document ID | / |
Family ID | 39268806 |
Filed Date | 2011-10-06 |
United States Patent
Application |
20110240531 |
Kind Code |
A1 |
Timmerman; Michael A. ; et
al. |
October 6, 2011 |
MAGNETIC SCREEN CLAMPING
Abstract
A magnetic clamping system for a shale shaker including at least
one screen having at least two side ends extending between a first
side and a second side and at least one attachment surface. The
system further includes at least one mating surface of the shale
shaker configured to receive the at least one screen, and at least
one magnet disposed between the at least one screen and the shale
shaker, wherein the at least one magnet is configured to
magnetically couple the at least one screen directly to the shale
shaker. Additionally, the system includes at least one decoupling
apparatus, the decoupling apparatus having a handle disposed
proximate a perimeter of a shale shaker, and at least one shaft
that extends horizontally between the handle and one of the at
least one magnet, wherein the handle is rotatable to reverse the
polarity of the magnet.
Inventors: |
Timmerman; Michael A.;
(Cincinnati, OH) ; Holton; Benjamin L.; (Dayton,
KY) ; Marshall, JR.; James A.; (Union, KY) ;
Carr; Brian S.; (Burlington, KY) |
Assignee: |
M-I L.L.C.
Houston
TX
|
Family ID: |
39268806 |
Appl. No.: |
13/083165 |
Filed: |
April 8, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11862895 |
Sep 27, 2007 |
7922003 |
|
|
13083165 |
|
|
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|
60827566 |
Sep 29, 2006 |
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Current U.S.
Class: |
209/405 |
Current CPC
Class: |
B07B 2201/02 20130101;
B07B 1/46 20130101; B07B 1/4627 20130101; B07B 1/4645 20130101 |
Class at
Publication: |
209/405 |
International
Class: |
B07B 1/46 20060101
B07B001/46 |
Claims
1. A magnetic clamping system for a shale shaker, the magnetic
clamping system comprising: at least one screen comprising at least
two side ends extending between a first side and a second side and
at least one attachment surface; at least one mating surface of the
shale shaker configured to receive the at least one screen, wherein
the shale shaker comprises a first end and a second end; at least
one magnet disposed between the at least one screen and the shale
shaker wherein the at least one magnet is configured to
magnetically couple the at least one screen directly to the shale
shaker; and at least one decoupling apparatus comprising: a handle
disposed proximate a perimeter of the shale shaker; and at least
one shaft that extends horizontally between the handle and one of
the at least one magnet, wherein the handle is rotatable to reverse
the polarity of the magnet.
2. The magnetic clamping system of claim 1, wherein the at least
one decoupling apparatus is configured to decouple the at least one
magnet from the at least one attachment surface.
3. The magnetic clamping system of claim 1, wherein the at least
one decoupling apparatus is configured to decouple the at least one
magnet from the at least one mating surface.
4. The magnetic clamping system of claim 1, wherein the at least
one magnet is disposed proximate the center of at least one side
end of the at least one screen.
5. The magnetic clamping system of claim 1, wherein the at least
one magnet is disposed proximate at least one corner of the at
least one screen.
6. The magnetic clamping system of claim 1, wherein the at least
one magnet is a permanent rare earth magnet.
7. The magnetic clamping system of claim 1, wherein the at least
one screen is a composite screen comprising a carbon steel cage
encased in polymer.
8. The carbon steel cage of claim 7, further comprising at least
one metal plate attached to an attachment surface of the at least
one screen.
9. The magnetic clamping system of claim 1, wherein the at least
one screen comprises a metal frame.
10. The magnetic clamping system of claim 1, wherein at least one
of a group consisting of at least one mating surface and at least
one attachment surface comprises an element that responds to
magnetic force.
11. The magnetic clamping system of claim 1, wherein the at least
one screen comprises a first screen and a last screen.
12. The magnetic clamping system of claim 11, wherein the at least
one magnet extends from proximate the first side of the first
screen to proximate the second side of the last screen, and wherein
the at least one magnet is disposed proximate at least one of the
at least two side ends.
13. The magnetic clamping system of claim 11, wherein the at least
one magnet extends from proximate the first side of the first
screen to proximate the second side of the last screen, and is
disposed a selected distance between the first end and second end
of the shale shaker, and further comprising: at least one stop
track disposed proximate a midpoint of at least one of the at least
two side ends and configured to hold the at least one screen in
position.
14. The magnetic clamping system of claim 1, wherein the at least
one screen comprises a first screen and a second screen, the first
screen disposed adjacent the second screen, wherein an attachment
surface of the first screen and a second attachment surface of the
second screen are magnetically coupled to the at least one magnet
that extends from the first end to the second end of the shale
shaker, wherein the at least one magnet is aligned proximate at
least one of a group consisting of the first side and the second
side of the at least one screen, and wherein the at least one
magnet is attached to at least one screen support.
15. The magnetic clamping system of claim 1, wherein the at least
one magnet comprises a plurality of adjacent individual
magnets.
16. The magnetic clamping system of claim 1, wherein the at least
one attachment surface further comprises at least one magnet.
17. The magnetic clamping system of claim 1, wherein the at least
one mating surface further comprises at least one magnet.
18. The magnetic clamping system of claim 1, further comprising a
decoupling apparatus comprising an air actuated magnet with a
pneumatic signal.
19. The magnetic clamping system of claim 1, further comprising a
decoupling apparatus comprising a crank that moves a cam disposed
adjacent a screen of the shale shaker.
20. The magnetic clamping system of claim 1, wherein the at least
one screen comprises a first screen and a second screen, and
wherein the at least one shaft extends horizontally from proximate
the first side of the first screen to proximate the second side of
the second screen.
21. The magnetic clamping system of claim 1, wherein the shaft is
integrally formed with the handle.
22. The magnet clamping system of claim 1, wherein the handle is
configured to move the at least one magnet.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation application, and
thus claims benefit pursuant to 35 U.S.C. .sctn.121, of U.S. patent
application Ser. No. 11/862,895 filed on Sep. 27, 2007, currently
pending, which claims priority under 35 U.S.C. .sctn.119(e) to U.S.
Provisional Application No. 60/827,566, filed Sep. 29, 2006. The
contents of these applications are incorporated herein by
reference.
BACKGROUND OF INVENTION
[0002] 1. Field of the Invention
[0003] The present disclosure relates to methods and devices for
clamping filter screens for oilfield shale shakers. More
particularly, the present disclosure relates to magnetic clamps for
securing filter screens in position.
[0004] 2. Background Art
[0005] Oilfield drilling fluid, often called "mud," serves multiple
purposes in the industry. Among its many functions, the drilling
mud acts as a lubricant to cool rotary drill bits and facilitate
faster cutting rates. Typically, the mud is mixed at the surface
and pumped downhole at high pressure to the drill bit through a
bore of the drillstring. Once the mud reaches the drill bit, it
exits through various nozzles and ports where it lubricates and
cools the drill bit. After exiting through the nozzles, the "spent"
fluid returns to the surface through an annulus formed between the
drillstring and the drilled wellbore.
[0006] Furthermore, drilling mud provides a column of hydrostatic
pressure, or head, to prevent "blow out" of the well being drilled.
This hydrostatic pressure offsets formation pressures thereby
preventing fluids from blowing out if pressurized deposits in the
formation are breeched. Two factors contributing to the hydrostatic
pressure of the drilling mud column are the height (or depth) of
the column (i.e. the vertical distance from the surface to the
bottom of the wellbore) itself and the density (or its inverse,
specific gravity) of the fluid used. Depending on the type and
construction of the formation to be drilled, various weighting and
lubrication agents are mixed into the drilling mud to obtain the
right mixture. Typically, drilling mud weight is reported in
"pounds," short for pounds per gallon. Generally, increasing the
amount of weighting agent solute dissolved in the mud base will
create a heavier drilling mud. Drilling mud that is too light may
not protect the formation from blow outs, and drilling mud that is
too heavy may over invade the formation. Therefore, much time and
consideration is spent to ensure the mud mixture is optimal.
Because the mud evaluation and mixture process is time consuming
and expensive, drillers and service companies prefer to reclaim the
returned drilling mud and recycle it for continued use.
[0007] Another significant purpose of the drilling mud is to carry
the cuttings away from the drill bit at the bottom of the borehole
to the surface. As a drill bit pulverizes or scrapes the rock
formation at the bottom of the borehole, small pieces of solid
material are left behind. The drilling fluid exiting the nozzles at
the bit acts to stir-up and carry the solid particles of rock and
formation to the surface within the annulus between the drillstring
and the borehole. Therefore, the fluid exiting the borehole from
the annulus is a slurry of formation cuttings in drilling mud.
Before the mud can be recycled and re-pumped down through nozzles
of the drill bit, the cutting particulates must be removed.
[0008] One type of apparatus used to remove cuttings and other
solid particulates from drilling mud is commonly referred to in the
industry as a "shale shaker." A shale shaker, also known as a
vibratory separator, is a vibrating sieve-like table upon which
returning used drilling mud is deposited and through which
substantially cleaner drilling mud emerges. Typically, the shale
shaker is an angled table with a generally perforated filter screen
bottom. Returning drilling mud is deposited at the top of the shale
shaker. As the drilling mud travels down the incline toward the
lower end, the fluid falls through the perforations to a reservoir
below thereby leaving the solid particulate material behind. The
combination of the angle of inclination with the vibrating action
of the shale shaker table enables the solid particles left behind
to flow until they fall off the lower end of the shaker table.
[0009] The above described apparatus is illustrative of one type of
shale shaker known to those of ordinary skill in the art. In
alternate shale shakers, the top edge of the shaker may be
relatively closer to the ground than the lower end. In such shale
shakers, the angle of inclination may require the movement of
particulates in a generally upward direction. In still other shale
shakers, the table may not be angled, thus the vibrating action of
the shaker alone may enable particle/fluid separation. Regardless,
table inclination and/or design variations of existing shale
shakers should not be considered a limitation of the present
disclosure.
[0010] Preferably, the amount of vibration and the angle of
inclination of the shale shaker table are adjustable to accommodate
various drilling mud flow rates and particulate percentages in the
drilling mud. After the fluid passes through the perforated bottom
of the shale shaker, it may either return to service in the
borehole immediately, be stored for measurement and evaluation, or
pass through an additional piece of equipment (e.g., a drying
shaker, a centrifuge, or a smaller sized shale shaker) to remove
smaller cuttings and/or particulate matter.
[0011] Because shale shakers are typically in continuous use,
repair operations, and associated downtimes, need to be minimized
as much as possible. Often, the filter screens of shale shakers,
through which the solids are separated from the drilling mud, wear
out over time and subsequently require replacement. Therefore,
shale shaker filter screens are typically constructed to be quickly
removable and easily replaceable. Generally, through the loosening
of several bolts, the filter screen may be lifted out of the shaker
assembly and replaced within a matter of minutes. While there are
numerous styles and sizes of filter screens, they generally follow
similar design.
[0012] Typically, filter screens include a perforated plate base
upon which a wire mesh, or other perforated filter overlay, is
positioned. The perforated plate base generally provides structural
support and allows the passage of fluids therethrough. While many
perforated plate bases are flat or slightly arched, it should be
understood that perforated plate bases having a plurality of
corrugated or pyramid-shaped channels extending thereacross may be
used instead. Pyramid-shaped channels may provide additional
surface area for the fluid-solid separation process while guiding
solids along their length toward the end of the shale shaker from
where they are disposed.
[0013] In some shale shakers a fine screen cloth is used with the
vibrating screen. The screen may have two or more overlying layers
of screen cloth or mesh. Layers of cloth or mesh may be bonded
together and placed over a support, supports, or a perforated or
apertured plate. The frame of the vibrating screen is resiliently
suspended or mounted upon a support and is caused to vibrate by a
vibrating mechanism (e.g., an unbalanced weight on a rotating shaft
connected to the frame). Each screen may be vibrated by vibratory
equipment to create a flow of trapped solids on top surfaces of the
screen for removal and disposal of solids. The fineness or
coarseness of the mesh of a screen may vary depending upon mud flow
rate and the size of the solids to be removed.
[0014] In typical shakers, a screen or screen assembly is
detachably secured to the vibrating shaker machine. With the screen
assembly or multiple screen assemblies secured in place, a tray is
formed with the opposed, parallel sidewalls of the shaker. The
drilling mud, along with drill cuttings and debris, is deposited on
the top of the screen assembly at one side. The screen assembly is
vibrated at a high frequency or oscillation by a motor or motors
for the purpose of screening or separating materials placed on the
screen. The liquid and fine particles will pass through the screen
assembly by the acceleration of the screen assembly and will be
recovered underneath. The solid particles above a certain size
migrate and vibrate across the screen or screens where they are
removed.
[0015] It is known that to obtain the proper vibration of the
screen assembly, slack in the screens must be discouraged. Any
slack in the screen produces an undesirable flapping action of the
screen, which reduces the effectiveness of the shaker vibration and
also results in increased wear of the screen. Accordingly, it is
known that the screen should be securely and tightly held down to
the vibrating machinery by an attachment mechanism.
[0016] One type of attachment mechanism includes hooks on each
longitudinal end of the screen assembly to connect to the shaker.
The shaker will have a channel-shaped drawbar on each side, which
mates with a corresponding hook on the screen assembly. The
drawbars are held in place by bolts or other fasteners. These are
detachably connected so that the screens may be replaced from time
to time. Such screens are referred to in the industry as "hookstrip
screens."
[0017] Typically, hookstrip screens are manufactured by first
forming a metal perforated plate (i.e., a backplate) which serves
as support structure for the screen assembly. The metal perforated
plate is often heavy, expensive to manufacture, and blocks a
substantial portion of potential screen area. During screen
manufacture, a screen surface (i.e., a filtering element) is
attached to the metal perforated plate with powder epoxy. When the
powder epoxy is melted, and the screen surface attached to the
metal perforated plate, the epoxy spreads over the screen surface
thereby blocking screening surface. The bonding process is also
relatively long, in some instances lasting anywhere from 5 to 15
minutes.
[0018] In another type of current attachment mechanism, illustrated
in FIG. 1, a shaker screen 11 is typically installed in, or secured
to, shaker 10 with a wedge block 12 and a wedge block retainer
bracket 14. The wedge block retainer bracket 14 may be an integral
part of the shaker. The screen 11 is placed in position underneath
the wedge block retainer bracket 14 and then the wedge block 12 is
pounded into position so as to secure the screen 11 to the shaker
10. The operator often chooses to use a combination of a hammer and
a suitable piece of wood in contact with the wedge block 12 to
deliver sufficient force to fully tighten the wedge block. While
the current wedge block system may be effective for installing
screens, removing screens and replacing them using this method may
take considerable time and be labor intensive.
[0019] Accordingly, there exists a need for a cost efficient
attachment mechanism that does not substantially block a screening
surface for the filtering of drilling fluids. Also, there exists a
need for a quicker method of removing and installing screens.
SUMMARY OF INVENTION
[0020] In one aspect, embodiments disclosed herein relate to a
magnetic clamping system for a shale shaker including at least one
screen having at least two side ends extending between a first side
and a second side and at least one attachment surface, at least one
mating surface of a shale shaker configured to receive at least one
screen, wherein the shale shaker has a first end and a second end,
and at least on magnet disposed between the at least one screen and
the shale shaker, wherein the at least one magnet is configured to
magnetically couple the at least one screen to the shale
shaker.
[0021] In another aspect, embodiments disclosed herein relate to a
method for replacing a screen in a shale shaker, the method
including activating at least one decoupling apparatus, wherein a
magnetic clamping system includes the at least one decoupling
apparatus, removing at least one screen from the shale shaker,
deactivating the at least one coupling apparatus, and installing at
least one screen into the shale shaker.
[0022] Other aspects of the present disclosure will be apparent
from the following description and appended claims.
BRIEF DESCRIPTION OF DRAWINGS
[0023] FIG. 1 shows a conventional shale shaker and wedge block
system.
[0024] FIGS. 2A-2C is a shale shaker in accordance with embodiments
disclosed herein.
[0025] FIGS. 3A and 3B show filter screens in accordance with
embodiments disclosed herein.
[0026] FIGS. 4A and 4B show filter screens in accordance with
embodiments disclosed herein.
[0027] FIGS. 5A and 5B show a shale shaker in accordance with
embodiments disclosed herein.
[0028] FIGS. 6A and 6B show a shale shaker in accordance with
embodiments disclosed herein.
[0029] FIGS. 7A-7D show a shale shaker in accordance with
embodiments disclosed herein.
[0030] FIGS. 8A-8C show a shale shaker in accordance with
embodiments disclosed herein.
[0031] FIGS. 9A and 9B show a horizontally extending shaft for a
decoupling apparatus in accordance with embodiments disclosed
herein.
[0032] FIGS. 10A and 10B show a cam and crank system for a
decoupling apparatus in accordance with embodiments disclosed
herein.
[0033] FIG. 11 shows an air/hydraulic bellow style actuator for a
decoupling apparatus in accordance with embodiments disclosed
herein.
DETAILED DESCRIPTION
[0034] Generally, embodiments disclosed herein relate to methods
and devices for attaching filter screens to oilfield shale shakers.
Specifically, embodiments disclosed herein relate to magnets that
magnetically couple screens to a shaker. Further, embodiments
disclosed herein relate to a method of installing and removing a
screen for a shale shaker.
[0035] Referring initially to FIG. 2A, a top view of a shaker
basket 105 having a magnetic clamping system 15 in accordance with
one embodiment of the present disclosure is shown. In this
embodiment, the shaker 105 includes at least one filter screen 21.
Each screen 21 has two side ends 23 extending between a first side
28 and a second side 29. Additionally, the screen 21 may include a
composite frame, a wire structure and at least one filtering
element. While four screens 21 are shown in FIG. 2A, one of
ordinary skill in the art will appreciate that any number of
screens and configuration of screens may be used without departing
from the scope of the present disclosure. For example, in one
embodiment there may be one row of four screens or in another
embodiment, their may be two rows of four screens.
[0036] Referring now to FIGS. 2B and 2C, in one embodiment,
magnetic clamping system 15 is shown. The magnetic clamping system
15 may include an attachment surface 26, which may be any area on
the bottom surface of one or more screens 21 configured to
magnetically couple to at least one magnet 22, wherein the magnet
22 may be attached to any area on the shaker basket 105 configured
to receive attachment surface 26 of screen 21. Thus, attachment
surface 26 may include an element such as iron, steel, or any other
material known in the art that responds to a magnetic force. The
magnet 22 may include a mating surface 27 configured to couple with
attachment surface 26. Alternatively, in one or more embodiments,
one of ordinary skill in the art will appreciate that a magnet may
be integrally formed (not shown) within the shaker basket 105, such
that mating surface 27 forms a portion of the shaker basket 105
configured to receive attachment surface 26. In another
alternative, one or more embodiments may include at least one
magnet (not shown) attached to screen 21, such that the
corresponding magnet 22 attached to shaker basket 105 and the
magnet attached to screen 21 are configured to magnetically couple
together, thereby securing screens 21 to the shaker basket 105.
[0037] Still referring to FIGS. 2B and 2C, when attachment surface
26 of screen 21 is disposed proximate mating surface 27, the
magnetic force between magnet 22 and attachment surface 26 secures
screen 21 to shaker basket 105. As shown, at least one magnet 22
may be disposed proximate a center of each side end 23 of each
screen 21. One of ordinary skill in the art will appreciate that
magnet 22 may be attached to any portion of the shaker basket 105
(e.g., sides of shaker basket 105) by any means known in the art,
for example, bolting, gluing, or welding.
[0038] In one embodiment, a screen 21 may include a composite
frame. A composite frame may be formed from any material known to
one of ordinary skill in the art including, but not limited to,
plastics or combinations of stainless steel, metal alloys,
plastics, etc. Composite frames in accordance with embodiments of
the present disclosure may be formed by a number of methods known
to those of ordinary skill in the art of plastics manufacture. One
such method of forming composite frames may include injection
molding and/or gas injection molding. In such an embodiment, a
composite or polymer material may be formed around a wire structure
and placed in a mold. The mold may be closed around the wire
structure and a liquid polymer injected therein. Upon curing, a
force may be applied to opposing sides of the mold thereby allowing
the formed frame to separate from the mold. In alternate methods of
injection molding, gas may be injected into a mold to create spaces
in the composites that may later be filled with alternate
materials. In another embodiment, these spaces may be filled with
elements that respond to magnetic force, such as iron, steel or
other material known in the art. Alternatively, these spaces may be
filled with a magnetic material.
[0039] As illustrated in FIGS. 3A and 3B, screen 21 may also be
formed to include a metal perforated plate 30 (e.g., a backplate)
which is attached to the bottom surface of the screen 21. In one
embodiment, the plate 30 may be attached with a powder epoxy. In
this embodiment, the powder epoxy is melted and disposed between
the bottom surface of the screen 21 and the metal perforated plate
30. Thus, the plate 30 is able to respond to magnetic force. One of
ordinary skill in the art will appreciate that a magnet (not shown)
attached to a shaker basket (not shown) may couple with the
perforated plate 30 in order to secure screen 21 to the shaker
basket.
[0040] In another embodiment shown in FIGS. 4A and 4B, screen 21
may also be formed to include at least one metal plate 35. One of
ordinary skill in the art will appreciate that the metal plate may
either be attached to the screen 21, or integrally formed with the
screen 21. Thus, the metal plate 35, configured to respond to
magnetic force, may couple the screen 21 to a magnet (not shown)
attached to a shaker basket (not shown). Accordingly, in this
embodiment, the screen may be secured to a shaker basket when the
metal plate 35 is coupled to the corresponding magnet. One of
ordinary skill in the art will appreciate that the metal plate 35
is approximately the size of the magnet.
[0041] Referring now to FIGS. 5A and 5B, screen 21 may include at
least one magnet 22 attached to an attachment surface 26 of screen
21. Further, at least a portion of shaker basket 105, referred to
as mating surface 27, may comprise an element such as iron, steel,
or any other material known in the art that responds to a magnetic
force. Each mating surface 27 of shaker basket 105 is located in a
position configured to receive the attachment surface 26 of screen
21. In this embodiment, the magnet 22 is configured to couple to
the corresponding mating surface 27, thereby magnetically coupling
the screen 21 to the mating surface 27 of shaker basket 105. The
magnet 22 may be attached to the attachment surface 26 of screen 21
by any method known in the art, for example, bolting, screwing,
welding, or an equivalent thereof In this embodiment, the mating
surface 27 may include an element such as iron, steel, or any other
material known in the art that responds to a magnetic force. As
screen 21 is placed into the shaker basket 105, the magnets 22
attached to the attachment surface 26 of the screen may couple with
the mating surface 27 of the shaker basket 105.
[0042] Alternatively, one of ordinary skill will appreciate that in
one or more embodiments, at least one magnet may also be attached
to the shaker basket 105, such that at least one unattached end of
the magnet is the mating surface 27 configured to couple with the
corresponding magnet 22. Thus, the magnetic coupling between the
magnet 22 attached to the screen 21 and the magnet (not shown)
attached to the shaker basket 105 secures the screen 21 to the
shaker basket 105. While four screens 21 are shown in FIG. 2A, one
of ordinary skill in the art will appreciate that any number of
screens and configuration of screens may be used without departing
from the scope of the present disclosure. For example, in one
embodiment there may be one row of four screens or in another
embodiment, their may be two rows of four screens.
[0043] Referring now to FIG. 5B, a top view of a shaker basket 105
is shown having a magnetic clamping system 115 in accordance with
this embodiment. The magnetic clamping system 133 includes all of
the structural features as illustrated in FIGS. 2A-2C, however,
magnets 22 may be positioned at different locations. As
illustrated, at least one magnet 22 may be disposed proximate each
corner of each screen 21. Those of ordinary skill in the art will
appreciate that while certain numbers and locations of magnets 22
and mating surfaces 27 are shown, any number of combinations may be
used.
[0044] Turning now to FIG. 6A, a top-view of a shaker basket 105
having a magnetic clamping system 215 in accordance with another
embodiment of the present disclosure is shown. In this embodiment,
the shaker basket 105 has a first end 24 and a second end 25, and
includes at least one filter screen 21. Each screen 21 has two side
ends 23 extending between a first side 28 and a second side 29.
Additionally, screen 21 may include a composite frame, a wire
structure and at least one filtering element.
[0045] Referring now to FIG. 6B, in one embodiment, each screen 21
includes an attachment surface 26. Attachment surface 26 may be any
area on the bottom surface of the screen 21 configured to
magnetically couple to one or more magnets 64. Thus, attachment
surface 26 may include an element such as iron, steel, or any other
material known in the art that responds to a magnetic force. The
magnetic clamping system 215 of this embodiment may include two
magnets 64 attached to the shaker basket 105. Each magnet 64 may
include a mating surface 27 configured to magnetically couple with
the corresponding attachment surface 26. The magnet 64 may be
attached to any area on the shaker basket 105 configured to receive
attachment surface 26. In this embodiment, the magnet 64 may be
attached to the top surface of at least one screen support 122. The
screen support 122 forms a portion of the shaker basket 105. When
attachment surface 26 of screen 21 is disposed proximate mating
surface 27 of magnet 64, the magnetic force between magnet 64 and
attachment surface 26 secures screen 21 to shaker basket 105.
Alternatively, one of ordinary skill in the art will appreciate
that in one or more embodiments, a magnet (not shown) may instead
be fixed to the attachment surface 25 of screen 21 and the shaker
basket 105 may comprise one or more mating surfaces 27 (e.g., top
surface of screen support 122) comprising an element such as iron,
steel, or any other material known in the art that responds to a
magnetic force. Accordingly, the magnet 64 may be configured to
magnetically couple to the mating surface 27 of the shaker basket
105, thereby securing the screen 21 to the shaker basket 105. In
other embodiments, a magnet (not shown) may be attached to the top
surface of at least one screen support 122 and a magnet may be
fixed to the attachment surface 25 of screen 21.
[0046] Still referring to FIG. 6B, each magnet 64 may extend
horizontally along shaker basket 105, extending from proximate the
first side 28 of first screen 21a to proximate the second side 29
of last screen 21 d. One magnet 64 may be disposed proximate to the
first end 24 and another magnet 64 disposed proximate to the second
end 25. One of ordinary skill in the art will appreciate that
magnet 64 may be attached by any method known in the art, for
example, bolting, gluing, welding, or equivalent thereof Further,
those of ordinary skill in the art will appreciate that while
certain numbers, sizes, and locations of magnets 64 and mating
surfaces 27 are shown, any number of combinations may be used.
[0047] A top view of a shaker basket 105 having a magnetic clamping
system 315 in accordance with another embodiment of the present
disclosure is shown in FIGS. 7A-7D. This embodiment includes all of
the structural features as illustrated in FIGS. 6A-6B, however, at
least one magnet 64 may be positioned at a different location. As
illustrated in FIGS. 7A and 7B, at least one magnet 64 may extend
horizontally along the length of the shaker basket 105 extending
from proximate the first side 28 of first screen 21 a to proximate
the second side 29 of last screen 21 d.
[0048] FIG. 7C is an end view of the embodiment shown in FIGS. 7A
and 7B. As illustrated, at least one magnet 64 may be disposed a
selected distance between the first end 24 and second end 25 of the
shaker basket 105. As the center of each screen 21 is drawn
downward by the force of magnet 64, the side ends 23 of each screen
21 may shift upwards. To prevent the displacement of each screen
21, at least one stop track 110 may be disposed proximate each
midpoint of each screen side end 23, shown in FIGS. 7C-7D. Stop
track 110 may be configured to hold at least one screen 21 in
position. One of ordinary skill in the art will appreciate that
stop track 110 may be composed of metals, plastics, or any material
equivalent thereof. Further, one of ordinary skill in the art will
appreciate that while certain numbers and locations of magnets 64
and stop tracks 23 are provided in embodiments disclosed, any
number of combinations may be used.
[0049] In another embodiment, at least one magnet 64 may include
adjacent individual magnets (not shown). This embodiment includes
all of the structural features as illustrated in FIG. 7A, however,
an array of magnets (not shown) may be disposed along the length of
the shaker basket 105, such that when screens 21a-21d are disposed
in shaker basket 105, they are substantially aligned with magnets
64. In one embodiment, a plurality of magnets (not shown) may be
disposed adjacent one another. This arrangement of magnets may form
a magnetic circuit positioned to achieve a particular magnetic
field. For example, a magnetic circuit formed from the arrangement
of magnets may provide magnetic flux into designated air gaps via,
for example, metal components, thereby increasing the magnetic hold
between the screens 21a-21d and the shaker basket 105.
[0050] Alternatively, this embodiment may include at least one
magnet (not shown) that is attached to an attachment surface 26 of
a screen 21 and is configured to couple the screen 21 to the mating
surface 27 of a shaker basket 105. For example, at least one magnet
(not shown) may be attached to the attachment surface 26 of a
screen 21 by any method known in the art, for example, by bolting,
gluing, welding, or any equivalent thereof As the screen 21 is
placed into the shaker basket 105, the magnets (not shown) attached
to the attachment surface 26 of the screen 21, may couple to the
mating surface 27 of the shaker basket 105. In this embodiment, the
mating surface 27 may include an element that responds to magnetic
force such as iron, steel, or any equivalent thereof known to an
ordinary person skilled in the art.
[0051] Referring now to FIGS. 8A-8C, a top view of an alternate
magnetic clamping system 415 in accordance with one embodiment of
the present disclosure is shown. In this embodiment, the shaker
basket 105 has a first end 24 and a second end 25, and includes at
least one screen 21. Each screen 21 has two side ends 23 extending
between a first side 28 and a second side 29. Additionally, each
screen 21 may include a composite frame, a wire structure and at
least one filtering element. In this embodiment, the bottom surface
of each screen includes an attachment surface 112, that may include
an element that responds to magnetic force such as iron, steel, or
any equivalent thereof known to an ordinary person skilled in the
art. Further, the magnetic clamping system 415 of this embodiment
may include at least one magnet 120 attached the shaker basket 105.
The portions of the shaker basket attached to corresponding magnet
120 are referred to as mating surface 27. In this embodiment, the
mating surface 27 may be the top surface of at least one screen
support 122. At least one magnet 120 may extend from the first end
24 to the second end 25 of the shaker basket 105. Further, magnet
120 may be aligned proximate to a first side 28 or second side 29
of a screen 21. One of ordinary skill in the art will appreciate
that the magnet 120 may be attached by any method known in the art,
for example, by bolting, gluing, welding, or any equivalent
thereof.
[0052] Referring now to FIG. 8C, in this embodiment, the attachment
surface 112 of one screen 21a and an attachment surface 112 of an
adjacent screen 21b are magnetically coupled to the same magnet
120. At least one magnet 120 may be disposed proximate to adjacent
sides of a screen 21, such that while the magnet 120 exerts force,
the screen 21 may be securely fastened to the shaker basket 105.
One of ordinary skill in the art will appreciate that magnet 120
may be of any shape or size without departing from scope of
embodiments disclosed herein.
[0053] Referring back to FIGS. 5A and 5B, in one embodiment, a
decoupling apparatus 175 for decoupling screens 21 from shaker
basket 105 is shown. At least one handle 32 is disposed proximate
to perimeter of shaker basket 105 and is configured to reverse
polarity of at least one magnet 22. Alternatively, in another
embodiment (not shown), handle 32 may be disposed proximate to each
magnet 22. As each handle 32 is turned, each corresponding magnet
22 rotates 180 degrees, thereby reversing polarity of each magnet
22. In this embodiment, each handle 32 controls the corresponding
magnet 22 attached to the shaker basket 105, and magnetically
coupled to the attachment surface 26 of each screen 21. One of
ordinary skill in the art will appreciate that the handle 32 may be
composed of any material known in the art and can be attached by
any method, such as bolting, screwing or any equivalent method
thereof. Further, one of ordinary skill in the art will appreciate
that while certain numbers and locations of magnets 22 and handles
32 are provided in embodiments disclosed herein, a number of
combinations may be used.
[0054] In another embodiment, as shown in FIGS. 9A and 9B, a
decoupling apparatus 177 for decoupling screens 21 from shaker
basket 105 is shown. At least one handle 32 disposed proximate to a
perimeter of shaker basket 105 is configured to rotate a shaft 54.
In this embodiment, at least one shaft 54 may extend horizontally
from a first side 28 of the first screen 21a to the second side 29
of the last screen 21d. At least one shaft 54 may be configured to
reverse polarity of an entire side of magnets 22. For example,
referring to the cross sectional view of FIG. 9A, the shaft 54 may
rotate the magnets 22 180 degrees, thereby reversing the polarity
of the magnets 22. The position of the handle 32 in this embodiment
is further illustrated in FIGS. 6A and 6B. Thus, in this example,
the magnetic circuit may be broken or altered by moving one or more
magnets.
[0055] In another embodiment, as shown in FIGS. 10A and 10B, an
alternate decoupling apparatus 179 for decoupling screens 21 from
shaker basket 105 is shown. At least one crank 132 is disposed
proximate to the perimeter of the shaker basket 105, and configured
to rotate at least one cam 130 disposed within the shaker basket
105. One of ordinary skill in the art will appreciate that the cam
130 and crank 132 are composed of materials known in the current
art such as metal, plastics, etc. and are attached by any method
known in the art, for example, bolting, screwing, or any equivalent
method. In this embodiment, as the crank 132 is rotated, the cam
130 rises within the shaker basket 105 to press up against the
bottom surface of each screen 21 and thereby raising it from the
shaker basket 105. Further, one of ordinary skill in the art will
appreciate that while certain numbers and locations for cams 130,
and cranks 132 are provided in embodiments, a number of
combinations may be used.
[0056] Referring now to FIG. 11, an alternate decoupling apparatus
181 for decoupling screens 21 from shaker basket 105 is shown. At
least one hydraulic actuator 140 may be disposed within the shaker
basket 105 and below screen 21, and may be configured to press up
against the screen 21 and raise it from the shaker basket 105. For
example, the decoupling apparatus 181 may also include a piston
(not shown) that may fit tightly inside the opening of the
hydraulic actuator 140. In particular, the piston may be configured
to change the volume by exerting a force on the fluid enclosed by
the hydraulic actuator 140 The changing of volume may cause the
hydraulic actuator 140 to press up against the screen 21, or to
contract downward allowing the screen 21 to attach to the shaker
basket 105. One of ordinary skill in the art will appreciate that
inflatable screen gaskets, pneumatic actuators, air bellows, and
hydraulic bellows or equivalent methods known in the current art
may be used without departing from the scope of embodiments
disclosed herein.
[0057] In alternate embodiments, a decoupling apparatus for a
magnetic clamping system may include at least one air-actuated
magnet, wherein an air-actuated magnet functions such that it
provides clamping force at all times until it receives a pneumatic
signal. In another embodiment, an alternate decoupling apparatus
for a magnetic clamping system may include at least one
electromagnet. A wire may be disposed along the perimeter of the
shaker and an electric current runs therethough. In this
embodiment, switching off an electric current may deactivate at
least one electromagnet, thereby releasing its magnetic force. One
of ordinary skill in the art will appreciate that an electromagnet
may be composed of materials that when disposed proximate an
electric current, takes on magnetic properties.
[0058] In the embodiments disclosed above, a magnet is attached to
a surface of a screen and/or a component of a shaker basket. In
alternate embodiments, a magnet may be placed or formed within a
screen or shaker basket component. For example, a screen may be
molded or formed with a magnet inside the frame of the screen. In
this embodiment, an attachment surface of the screen corresponds to
the location of the magnet within the screen. Thus, the magnetic
force of the magnet in the screen may magnetically couple the
screen to a corresponding mating surface of the shaker basket, as
discussed above.
[0059] Advantageously, embodiments of the aforementioned
apparatuses and methods may increase efficiency of shaker systems
for the separation of drilling fluid from drill cuttings. As such,
the cost of building, maintaining, and repairing shakers may be
reduced. For example, whereas prior art cycle times for securing
screens to shakers may take from 5-15 minutes, screens in
accordance with embodiments disclosed herein may be bonded in a
matter of seconds.
[0060] Finally, while the present disclosure has been described
with respect to a limited number of embodiments, those skilled in
the art, having benefit of this disclosure, will appreciate that
other embodiments can be devised which do not depart from the scope
of the invention as disclosed herein. Accordingly, the scope of the
invention should be limited only by the attached claims.
* * * * *